Herefore, a fifth wheel has been provided having outwardly projecting ears which are attached thereto by welding as illustrated in U.S. Pat. No. 4,119,330. These ears are adapted to be engaged by a stop carried by the underside of the trailer when the trailer is pivoted in extreme angular position on either side. It has long been recognized that it is important to limit the angular movement of the trailer with respect to the trailer in order to avoid damage to the vertical exhaust system carried just to the rear of and adjacent the sides of the cab of the tractor. Moreover, such limitation of movement of the trailer in respect of the tractor may in certain circumstances act as a deterent to jack-knifing of the tractor-trailer rig.
It is desirable to construct the fifth wheel in an integral configuration so that the wedge-shaped ears or stops which extend laterally of the fifth wheel side skirt portions may function in order to stabilize the rig while affording positive abutment or stop means for engagement by the stop mechanism carried by the trailer. In order to provide lateral stabilization of the trailer through engagement between the underside of the trailer with a laterally positioned ear, depending upon the direction in which the trailer tends to tilt, it is necessary that lubricating means be provided for the respective engaging surfaces. It is desirable that this be done through the application of grease to the fifth wheel. While grease channels have heretofore been provided in the upper surface of fifth wheels as illustrated in U.S. Pat. No. 4,119,330 such was not so critical because there was no integral surface projecting laterally of the side skirt portions presenting a special need for the continuous application of grease due to the magnified contact between the fifth wheel and the trailer at the wedge-shaped portions. By thus providing an integral construction such may be more rugged for providing lateral stability through engagement of adjacent surfaces. Adequate lubrication may be provided without impairment of strength in the fifth wheel.
Accordingly, it is an important object of this invention to provide a fifth wheel having integral wedge-shaped stop members extending laterally of the fifth wheel for providing stability and a rugged abutment or stop means for limiting the movement of the trailer with respect to the tractor while affording stability with adequate greasing of the laterally remote wedge portions of the fifth wheel.